To activate Kumena’s abilities, you may tap any untapped Merfolk you control, including one you haven’t controlled continuously since the beginning of your most recent turn. (Note that tapping the creature doesn’t use [the tap symbol].) For Kumena’s second and third abilities, this includes Kumena itself.

1/19/2018

Activating Kumena’s first ability after it has become blocked won’t cause it to become unblocked.